minnich



(No Model.)

S. B. MINNIOH.

GOMPENSATING BIT HOLDER.

No. 460,922. Patented Oct. 6, 1891.

' in: name MYERS co, flnotowma, m

UNITED STATES PATENT OFFICE.

SIMON MINNICH, OF LANDISVILLE, PENNSYLVANIA, ASSIGNOR TO MARY MINNIOII, OF SAME PLACE.

COMPENSATING BIT-HOLDER.

SPECIFICATION forming part of Letters Patent No. 460,922, dated October 6, 1891.

Application filed February 6, 1891. Serial No. 3801536. (N model.)

TO whom it y UOIwWH/I hold smaller drills; and Fig. '7 two sectional Be it known that I, SIMON B. MINNIUH, of views, each through the dotted line in the Landisville, in the county of Lancaster and other, of a portion of a modification of my in- State of Pennsylvania, have invented certain vention having four flexible arms, anda tanew and useful Improvements in a Compenpering socket clamp screw instead of the 55 sating Drill-Chuck or Bit-Holder; and I do clamp and set-screw, to compress the arms to hereby declare the following to be a full, clear, hold the drill. and exact description of the invention, such Reference being had to Fig. 1, O designates as will enable others skilled in the art to a drill-press having a vertical spindle m and [O which itappertains to make and use the same. a horizontal spindle '22, while A represents the 60 My invention relates to improvements in a chuck or drill-holder applied, in this instance, compensating chuck or drill holder of that to the vertical spindle m; but it is equally class in which a number of flexible arms, applicable to the horlzontal spindle '21.. straps, or wings have one end rigidly secured Referring to Figs. 2, 3, and i, the device A to the forward end of a shaft or mandrel consists of a shaft B, fitted closely into the 6 adapted to be pushed into the usual socket socket of the spindle m of the drill-press 0; formed about the axis of the spindle of the and to the lower end of the shaft B are rigidly ordinarylathe or drill-press and the other ends secured the upper ends of straps or arms C, of said arms adapted to engage the shank of by means of rivets or bolts and nuts 0. These a drill and to be compressed by a clamp and straps or arms C are made of properly-tem- 7o set-screw or any other suitable means to hold pered spring metal and may have any desired the drill in place. shapein cross-section. They have each an out- The object of the invention is to'provide a wardly-projecting curve or loop 0 and at the drill-chuck or bit-holder that will compensate lower extremity an angular lip 0 and along for the irregularities in the pressure of the the center line of the inner face a vertical V- usual feeding devices of lathes and drillshaped channel to engage the shank of the presses and the unevenness in density of the drill, Fig. 5. Embracing the lower ends of particles composing the bodies being drilled the arms and resting on the lips c is a clamp or bored, both of which are now so very de- D, through an end of which is tapped a set- 0 structive to the points or cutting-ends of the screw d to compress the arms and to hold the drills or bits in use, breaking or blunting or drill in place. A liner E (shown in perspecotherwise unfitting them to do good work. tive in Fig. 6) is placed in pairs between the The purposes of the invention are attained arms, as is plainly shown in Figs. 2 and 3, by the means and devices illustrated in the when it is desired to use drills having small 35 accompanying drawings, in which similar letdiameters. In this instance two arms are ters of reference designatelike parts throughshown as attached to the shaft B; but this out the several views. number may be increased, if desired, and in- Figure 1 is a side elevation of a power drillstead of the clamp and set-screws before depress having two spindles, showing the elescribed a tapering socket clamp-screw D 40 ments of my invention in place in the lower may be used to compress the lower ends of end of the vertical spindle; Fig. 2, an enlarged the arms to hold the drill, as is clearly shown side elevation of the chuck ordrill holder, dein the two views in Fig. 7. taehed from Fig. 1, the clamp appearing in An inspection of Fig.1 in the drawings will central vertical section; Fig. 3, a view from clearly show that should there be any excess- 5 the left of Fig. 2, the clamp being completed; ive pressure on the drill from the downward 5 Fig. 4, a View from below of Fig. 2 the drill force of the feed the flexibility of the arms, appearing in cross-section; Fig. 5, a similar by reason of the elasticity given them by the view as in Fig. 4., but the liners removed and loops 0, will instantly relieve the tool from a larger drill in cross-section in place; Fig. 6, said pressure, and should the cutting-edges 50 a perspective view of a liner used in pairs to of the drill come into sudden contact wit-h Ioo some hard obstruction in the body beingbored the flexibility of the arms, acting-'torsionally, will again relieve the tool. Hence it may be observed that my tool-holder is a compensatin g drill-chuck.

In the drawings, the arms 0 are shown as having the longitudinal center line of each lying entirely within aplane passing through the axis of the chuck; but I do not confine myself to this precise construction, for the curved portions of said arms may be given a spiral twist about said axis, when both their axial and torsional elasticity will be increased,

This latter construction being so simple and apparent, its separate illustration is deemed unnecessary. 

